Best known for his current starring role on the hit series “Castle”, Nathan Fillion first gained millions of fans for his portrayal of Captain Malcolm ‘Mal’ Reynolds on Joss Whedon’s acclaimed series, “Firefly”. He is also beloved by fans for his roles on “Buffy the Vampire Slayer”, “Serenity”, and for his unforgettable performance as Captain Hammer in “Dr. Horrible’s Sing-Along Blog”.